When are two or more grounding electrodes required?

Two or more grounding electrodes are required when the ground resistance exceeds the maximum value specified by the Canadian Electrical Code (CEC). This regulation exists to ensure adequate grounding, which is essential for both safety and the effective functioning of electrical systems. Grounding electrodes disperse fault currents into the earth to stabilize the voltage during normal operation and to protect against surges caused by lightning or other electrical disturbances.

If the resistance of a single grounding electrode is too high, it may not effectively provide the necessary ground fault path, which can increase the risk of electrical shock or fire. Therefore, employing multiple electrodes can lower the overall resistance and enhance the safety of the system.

While situations like installing pools or residential wiring have specific grounding requirements, they do not necessarily mandate the use of multiple electrodes unless accompanied by a high ground resistance, as defined by the CEC. Similarly, industrial applications can have different grounding considerations, but these do not restrict the requirement solely to that context. The primary focus remains on ensuring that adequate grounding resistance is achieved, highlighting the significance of the electrical safety standards set forth in the CEC.